The present invention relates to caliper disk brakes comprising at least one hydraulic working chamber intended for spacing apart from one another a piston bearing on one brake shoe and a caliper bearing on the other brake shoe.
It is known that the heat generated by the friction of the brake shoes on the braked disk is distributed rapidly in the brake as a whole because of the material used for producing the brake. In fact, this material is generally a metal, such as cast iron, intended to withstand very high mechanical stresses.
This heat is thus transmitted to the brake fluid which is located in the working chamber and which can thereby reach its evaporation temperature. Although a liquid is not compressible, vapor by contrast is. This can then result in serious disturbances in the functioning of the brake.
To overcome this problem, the document WO-A-89/11052 proposes using a ceramic piston of low thermal conductivity. However, such a piston is very costly and does not protect the brake fluid from the heat transmitted by the caliper.
With the same aim in view, the document JP-A-61-45120 proposes covering all the parts of the brake facing the disk with a ceramic material. But such a solution does not allow the heat generated on the disk to dissipate by way of the brake itself. This often results in a thermal expansion and burning of the linings.